Wireless Local Area Network (WLAN) technology enables more users to carry out a data service through a WLAN. With the development of services of users and the acceleration of WLAN construction by mobile operators, some services may be provided to a core network of the 3rd Generation Partnership Project (3GPP) of a mobile operator through a WLAN, so as to access self-operated services of the 3GPP operator. An S2a/b/c interface is introduced into 3GPP 23.402 to support interworking between an Evolved Packet Core (EPC) and non-3GPP. In an EPC architecture, a WLAN access network may be connected to a Packet Data Network Gateway (PGW) directly as a credit extension network through an S2a interface. The S2a interface performs information interaction through a General Data Transfer Platform (GTP) or a Proxy Mobile Internet Protocol (PMIP). Before accessing a WLAN, a user terminal will be authenticated first by a 3GPP Authentication, Authorization and Accounting (AAA) server. During the authentication process, the 3GPP AAA server and an Access Controller (AC) decide, through a Service Set Identifier (SSID) of the user, subscription information and a device support condition, whether the user terminal can access an EPC core network. When it is determined that the user terminal is allowed to access the core network, the AC selects, according to a default Access Point Name (APN) subscribed by the user terminal, a PGW corresponding to the APN and establishes a tunnel for connection. Service data sent by the user terminal may be sent to the core network through the tunnel and a target server is accessed through the core network. When it is determined that the user is not allowed to access the core network, service data sent by the user terminal is distributed to the Internet through the AC. A current protocol architecture allows making a service of the user terminal provided to the core network or distributing the service to the Internet. However, requiring all services of the user terminal to be provided to the core network or the Internet is the only one option if the service of the user terminal is provided to the core network or distributed to the Internet according to the subscription information of the user. However, demands of users become more diverse with the development of intelligent terminals. A user terminal may have different service demands at the same moment. When all services of the user terminal are provided to the core network, the load of data traffic of the core network will be increased, thus many services will race to control network services. If all services are distributed to the Internet, a self-operated service of an operator, e.g. a multimedia message and so on, can be hardly accessed, thereby causing a loss to the benefits of the operator.